I. Field of the Present Invention
The present invention relates generally to vehicle lamps having a bulb and socket assembly, the bulb of which is insertable into a reflector receptacle, and more particularly to a retainer for retaining the socket portion and preventing forced insertion of incompatibly configured sockets.
II. Description of the Prior Art
In order to overcome production and packaging expenses for large sealed beam vehicle headlamps, it has been considered advantageous to reduce the size of the envelope enclosing a lamp filament and to support the smaller envelope within an enlarged reflector assembly. One known type of such insertable lamps includes a socket housing which is adapted to be received within a receptacle in the reflector. Nevertheless, while the envelope and socket structure are readily available from the lamp manufacturer, the means for mounting the assembly in the receptacle has been left to the vehicle manufacturer as a durable part of the vehicle which does not require repeated replacement.
U.S. Pat. Nos. 4,528,619 and 4,507,712 to Dolan et al. disclose a light bulb socket and a reflector assembly in which the receptacle for the socket includes projections adapted to be received in slots formed peripherally on the socket body. The socket is retained in its inserted position by a cap having a lip which engages a peripheral groove on the socket and a resilient base segment engaging a rear surface of the socket. The patents also disclose that the cap may be provided with projecting segments which are received in recesses of an upstanding flange on the socket so that once the flange has passed the end of the cap, the socket can be rotated slightly so that the flange is retained under the projections.
These previously known constructions are disadvantageous for the reason that the formation of projections on the reflector and the cap as well as corresponding slots in the body of the socket substantially complicates the production of each of those components. In addition, high beam and low beam sockets may be formed with the same type of construction, and the references do not teach or suggest any means for avoiding inadvertent or forced installation of an improperly selected lamp socket within a receptacle intended for another lamp socket.
One previously known socket construction intended to avoid installation of an improperly selected socket within the receptacle involves the use of different diameter sockets for high and low beam lamp assemblies. Accordingly, the reflectors are constructed with receptacles correspondingly sized to receive the different sockets. Nevertheless, while it may be appreciated that the larger socket body could not be fit into the smaller receptacle, it would still be possible for a smaller socket to be received within the larger diameter receptacle.
A further previously known feature intended avoid such insertion involves the formation of an expanded flange on the lamp socket having projections in a predetermined alignment and wherein the predetermined alignment of the projection on the high beam socket differs from the circumferential spacing of the projections in the predetermined alignment on the low beam socket. However, in practice it has been found that known, available high beam and low beam socket structures have predetermined alignments which differ only by a slight offset of one of the projections, while the remaining two projections on each socket body remain similarly aligned. Moreover, the single projection on each type of socket which has been offset is offset only through a small angular variation such that it would still be possible to force installation of an improperly selected small diameter socket within a larger diameter receptacle by cocking or twisting the socket so as to align the offset projection with the slightly offset slot.
Thus, the previously known socket constructions have not eliminated the possibility of defective vehicle assembly by forced installation of improperly selected sockets in a receptacle. The inability to preclude such improper installation can cause substantial difficulties in the mass production of motor vehicles as well as in repair and replacement of the lamp sockets as is often required in normal maintenance.